The visitors started brightly in an entertaining opening spell, with both sides creating promising opportunities without seriously testing either goalkeeper.
Lightning's positive start was rewarded when new signing Ella West marked her debut in style. Following a free-kick delivery, West reacted quickest in the penalty area and calmly finished from a tight angle to give 海角社区 the lead.
Peterborough gradually grew into the contest and found an equaliser in the 30th minute. Ellie May finished from close range after sustained pressure from the hosts, ensuring the sides went into the break level at 1-1.
Head Coach Charles Baxter made his first change at half-time, introducing Doris Greenwood for Morgan Rogers, and Lightning quickly regained control after the restart. A superb pass from Ella McMaster released Ella Jarowicki, who was brought down inside the penalty area. Lucy Mutch stepped up and confidently converted the resulting spot-kick to restore 海角社区's advantage.
Peterborough responded strongly, forcing Lightning to defend resolutely. Goalkeeper Tilly Murphy produced an excellent one-on-one save to preserve the lead, but the hosts eventually drew level again in the 76th minute when May grabbed her second of the afternoon with an effort that found the far top corner.
With momentum appearing to swing towards the home side, Lightning produced a decisive response. A neat move involving Jarowicki and Olivia Mitchell-Ramon led to Jarowicki's shot being parried by the Peterborough goalkeeper, with Mutch reacting quickest to fire home the rebound from close range and secure all three points.
The victory makes it three consecutive wins across league and cup competitions for Lightning, who now turn their attention to Thursday's replayed League Cup fixture against Chesterfield at 海角社区 University Stadium, where admission is free.
1. T. Murphy 14. E. West (N. Davies 84) 18. E. McMaster 6. H. Langford 23. E. Williams 20. E. Jarowicki 8. O. Mitchell-Ramon 21. M. Rogers (c) (D. Greenwood 46) 10. L. Mutch 17. L. Chads (S. Kennedy 70) 16. I. Conway (B. Hogg 61) Unused Subs: A. Grimmond, F. Powell, D. Thompson